A position detection device having a pen-type position indicator for detecting a position by moving the pen on a position detection plane is called a digitizer, and is widely spread as an input device for computers. The position detection device includes a position detection flat plate, and a circuit board (sensor board) disposed therebelow and having loop coils formed on the surface of the board. Then, the position of the position indicator is detected by using electromagnetic induction generated by the position indicator and loop coils.
Patent Document 1 has proposed, for example, a method in which a soft magnetic film containing a soft magnetic material is disposed at a face (opposite face) opposite to the face of the position detection plane of the sensor board in a position detection device for efficient communication by controlling the magnetic flux generated at the time of electromagnetic induction.
Patent Document 1 discloses a magnetic film containing a soft magnetic powder, a binder resin composed of, for example, acrylic rubber, phenol resin, epoxy resin, and melamine, and a metal salt of phosphinic acid. The soft magnetic film has a high content of, for example, a metal salt of phosphinic acid and melamine, and therefore, fire-retardancy is given to the circuit board without affecting reliability of an electronic device.